/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.iotdb.flink;

import org.apache.flink.api.common.typeinfo.TypeInformation;
import org.apache.flink.api.common.typeinfo.Types;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.typeutils.RowTypeInfo;
import org.apache.flink.types.Row;
import org.apache.iotdb.flink.tsfile.RowRowRecordParser;
import org.apache.iotdb.flink.tsfile.TsFileInputFormat;
import org.apache.iotdb.tsfile.common.constant.QueryConstant;
import org.apache.iotdb.tsfile.read.common.Path;
import org.apache.iotdb.tsfile.read.expression.QueryExpression;

import java.io.File;
import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;

/**
 * The example of reading TsFile via Flink DataSet API.
 */
public class FlinkTsFileBatchSource {

    public static void main(String[] args) throws Exception {
        String path = "test.tsfile";
        TsFileUtils.writeTsFile(path);
        new File(path).deleteOnExit();
        String[] filedNames = {
                QueryConstant.RESERVED_TIME,
                "device_1.sensor_1",
                "device_1.sensor_2",
                "device_1.sensor_3",
                "device_2.sensor_1",
                "device_2.sensor_2",
                "device_2.sensor_3"
        };
        TypeInformation[] typeInformations =
                new TypeInformation[]{
                        Types.LONG, Types.LONG, Types.LONG, Types.LONG, Types.LONG, Types.LONG, Types.LONG
                };
        List<Path> paths =
                Arrays.stream(filedNames)
                        .filter(s -> !s.equals(QueryConstant.RESERVED_TIME))
                        .map(s -> new Path(s, true))
                        .collect(Collectors.toList());
        RowTypeInfo rowTypeInfo = new RowTypeInfo(typeInformations, filedNames);
        QueryExpression queryExpression = QueryExpression.create(paths, null);
        RowRowRecordParser parser =
                RowRowRecordParser.create(rowTypeInfo, queryExpression.getSelectedSeries());
        TsFileInputFormat<Row> inputFormat = new TsFileInputFormat<>(queryExpression, parser);
        ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
        inputFormat.setFilePath(path);
        DataSet<Row> source = env.createInput(inputFormat);
        List<String> result = source.map(Row::toString).collect();
        for (String s : result) {
            System.out.println(s);
        }
    }
}
